There are, have been, and always (?) will be profitable coins to mine. You seem to think everyone with a GPU mines on ETHash. Many people have already jumped off that ship into other algorithms!
They won't be profitable any longer after the enormous gpu mining power jumps from ETH to other coins. That will create a massive explosion in difficulties for all coins. Thats the main point here.
I still feel like we are not on the page here, guys. It's not about the fate of ETH, it's about mining power and difficulty of all altcoins.
It's also gonna loss its value and it is gonna go to the other alts so the other alts are gonna pump so you better are buying altcoins than mining equipment